Suggested by General Electric in a 1970 document, this circuit uses a LASCR, or SCR fired by light. This component is uncommon today.
This circuit, for older machines, fires a second flash with the light received with the first, thus...
This circuit was found in a 90s Popular Electronics. The circuit indicates if a transmitter is working,...
Here is another project that is based on an astable multivibrator, in a demonstration of the...